Forums - Wiring SET into Mono !HELP!

mclark

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Wiring SET into Mono !HELP!
09/11/22 at 23:03:14

Hello All -
I have two SE84CKC(s) that I would like to wire into mono. I followed the .PDF of the owners manual (OWNERS MANUAL for Model SE84UFO PAGE 17).
Right away I noticed Amp 1 (Right Channel) had low volume, Amp 2 (Left Channel) very low w/ a lot of distortion. While chasing the 'bad' tube down... Always turning off and on. The fuse Popped on the power plug. Found a thread about blown fuse that said: pull rectifier, power on, every thing else lights up... amp = good, Rectifier may be bad. Did that - lit up - replaced rectifier. Both (Amp 1, Amp 2) Power up and work fine as SINGLE amps.

SO, I read the owners manual for SE84UFO2.1 (Bridging into Mono PAGE 7) - The Wiring description is DIFERENT from the .PDF graphic in (Model SE84UFO PAGE 17). This makes me wonder If the graphic is flawed?

QUESTION: Which is the correct way? I am totally confused...
I'm not sure if the .pdf graphic is the REASON why my rectifier zapped and blew the fuse. All connections were clean and clear and did not ground anything externally. (to the best of my knowledge).

HELP! I would like to get these wired into mono and take advantage of the 6 watts per side. As I said they are both working as single amps and I will be ordering some new output tubes. Any recommendations are appreciated.

Side Note: I have my first SE84C+ set up as reference with Tekton Lores (yes 3 amps total) and have found a bunch of old tubes at garage sales. Some look like they could be 'old unicorn magic' - Do I risk any damage switching/rolling 'unmarked' rectifiers?

Another Side Note: Refurbishing some old Allied Radio, Knight KN1286 with KN612HC 16ohm 12in woofers. Initial listen and thoughts seem promising - Anyone have with experience with these? Suggestions?

Thanks again - long time listener, first time caller!
Mike Clark

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CAJames

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Re: Wiring SET into Mono !HELP!
Reply #1 - 09/12/22 at 03:31:15

Are you trying to make balanced monos or "regular" monos? The diagram on page 17 of the UFO manual is for balanced. For that you need a balanced source and the custom XLR -> 2x RCA jumpers to break out the balanced signal into the L and R channel of the amps.

If you are looking for regular monos then the description on page 17 above the diagram is the same as the one in the UFO2.1 manual. This uses a RCA -> 2x RCA splitter to duplicate the signal into the L and R channel of the amp.

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mclark

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Re: Wiring SET into Mono !HELP!
Reply #2 - 09/12/22 at 19:28:10

Thanks CAJames -
Yes, I have the RACA/split not balanced. I guess I'm a more visual guy than verbal and missed that in the description. So, do you think I 'shorted' anything because I wired it goofy? They seem to be working fine after I replaced the rectifier. My channels are a little weak so I assume I need to replace the output tubes, also, do I need to replace the signal tubes to help achieve the 6watts - any particular tube recommendations?
Thanks again - your info about checking the amps 'health' without the rectifier installed saved my bacon!

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CAJames Seasoned Member Offline "I've run every red light on memory lane." Posts: 3270	Re: Wiring SET into Mono !HELP! Reply #3 - 09/12/22 at 19:33:34 I don't think you hurt anything the way you wired it, but you would expect little to no output. As for the tubes you may need to replace either or both the input and output tubes. Only way to know is to swap in known good tubes. Let us know how it goes.
Back to top	[Volumio \| Jay's CDT2 MRK3] -> Denafrips Terminator 2 + Gaia Sumiko Pearwood -> Mapleknoll Athena -> Luxman SUT -> Mapletree Phono 3E STR-1002 -> Woo WA22 -> 2x UFO25s, balanced monos Omega SAM , Hifiman Arya, Audeze LCD-XC IP Logged Share: Likes:

Dominick

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Re: Wiring SET into Mono !HELP!
Reply #4 - 09/13/22 at 02:49:10

Mike…I think you are in luck. I just recently purchased a SE84C+ CKC from a forum member. I was only getting sound out of one channel… so I thought it was a bad tube. After some investigation and a call to Decware, Sarah looked up Serial # and I found out that my amp is actually wired for mono.

I just sent it in for full upgrades, a warranty transfer, and to have it wired for stereo. Here is a picture of the inside of my amp

Hope this helps.

Dom

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mclark

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Re: Wiring SET into Mono !HELP!
Reply #5 - 09/15/22 at 19:03:21

Thanks Dominick - good idea. I'm pretty sure they're stereo but I'll get my serial #'s and email Sarah to verify.

I too have the an SE84C+ White (original owner). I've contemplated selling/trading but I'm IN LOVE with the white chassis. I've also considered doing an upgrading but I'm afraid it would make it more 'analytical' than 'musical' - not sure if that's correct? Maybe someone who's done the Mod can tell me if it's a good idea.

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Dominick

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Re: Wiring SET into Mono !HELP!
Reply #6 - 09/16/22 at 05:57:05

Mike….I am in LOVE with the white chassis as well. I have heard that the upgrade could make it more analytical in an untreated room. I believe Steve uses the Miflex caps now in all of his new amps and I’m sure they have a longer break in than the older beeswax caps before they open up. I have the Miflex caps in my new Torii MKIV 25th and quite honestly I have no complaints.

I was talking with Bob Ziegler (Ziggy) via PM he said one of the engineers from (I believe) Sonicraft who indicated that Miflex caps can take a while to break in, but once they open up he feels that there’s no other better cap out there.

If for some reason you decide to sell your SE84C+ White amp….please reach out to me first before you post it in the classifieds section. I will buy it from you no questions asked, so I can use it bridged as a mono pair.

Once I get my amp back from Decware, I’ll post my impressions to let you know how it sounds.

Dominick

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Lon

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Re: Wiring SET into Mono !HELP!
Reply #7 - 09/16/22 at 11:10:42

I really love the white chassis too, I had a Torii Mk III with that chassis and several CSP2+, one of which I still own and have had all the modifications done, including voltage tube regulation under chassis and I have to say it sounds fantastic. I am not using it at the moment but may use it very soon. Fantastic sounding as both a preamp and headphone amp. There is a certain magic to a very well seasoned Decware component.

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Dominick

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Re: Wiring SET into Mono !HELP!
Reply #8 - 09/17/22 at 08:30:09

Lon… I can only imagine how your CSP2 in the white chassis must look and sound with all of the upgrades. Decware now has my SE84C+ and I’m hoping within the next 2-3 weeks I should get it back with all of the upgrades.

After I get my ZROCK2…The next upgrade I plan to do to my system would be to upgrade my ZSTAGE for a better preamp like the CSP2. If you ever decide to part with your white CSP2 down the road...please me know. If the timing is right I would love the opportunity to buy it from you. With my home renovation… Our interior is basically a black and white farmhouse…. And my wife absolutely loves the white Zen Amp.

I’ll post my initial impressions of my upgraded Zen amp when I get it back.

Dom

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Lon

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Re: Wiring SET into Mono !HELP!
Reply #9 - 09/17/22 at 17:32:45

Dominick wrote on 09/17/22 at 08:30:09:

Lon… I can only imagine how your CSP2 in the white chassis must look and sound with all of the upgrades. Decware now has my SE84C+ and I’m hoping within the next 2-3 weeks I should get it back with all of the upgrades.

After I get my ZROCK2…The next upgrade I plan to do to my system would be to upgrade my ZSTAGE for a better preamp like the CSP2. If you ever decide to part with your white CSP2 down the road...please me know. If the timing is right I would love the opportunity to buy it from you. With my home renovation… Our interior is basically a black and white farmhouse…. And my wife absolutely loves the white Zen Amp.

I’ll post my initial impressions of my upgraded Zen amp when I get it back.

Dom

Dom, I'll keep that in mind. There was a time I entertained selling it as it has been sitting unused a while, but as I spent nearly 1000 dollars for Steve to do all the upgrades, and it has almost all the options as far as dual stereo output, stepped attenuator et al I would ask more for it than would entice a sale. I may put it back in use. . . something is telling me to try my CSP3 with the mods in place of the ZTPRE in the system, which I may try in the coming week or two, and if that works out I may need to put the CSP2+ in service in my audio/video system where the CSP3 now resides. Both the CSP2+ with the mods and the CSP3 with the mods are fantastic preamps and headphone amps--there is a slight difference between the two because the 2+ has a voltage regulation tube mod, and the 3 does not, but has a glass resistor bypassing the input volume controls.

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